It is now well-established that the development of alcoholism is influenced by genetic factors. The presence of genetic factors has led to a search for potential phenotypic markers. There is currently much scientific evidence to suggest that certain eventrelated potentials (ERP) anomalies are typically observed in young males found to be at high risk for developing alcoholism. Several investigators have reported that high risk males manifest a lower P3 amplitude of the ERP compared to low risk. We propose to develop data analytic techniques which will enable us to examine the amplitude of the P3 component in individual ERP trails. We plan to develop mathematical tools to estimate the potential sites of equivalent dipoles in a 3D model of the brain. Moreover, we will examine other ERP components such as P3a, Owave, N400, Readiness Potential and CNV in order to test specific hypotheses about young males (between 14 and 19 years) who are offsprings of male alcoholics with a multigenerational incidence of alcoholism. In addition we will test low risk subjects who will be matched on several demographic variables to high risk subjects. The identification of neurophysiological phenotypic markers may have clinical utility in the prevention of alcoholism.